<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>实现1到100相加求和</title>
    </head>
    <body>
        <script>
      var a = 1;
        var sum = 0;
        while ( a<=100 ){
           sum += a;
           a ++ ;
        }
        alert("1-100的数相加的和是" + sum);
</script>
</body>
</html>